ISSN:0030-4921    

DOI:10.1002/mrc.1270220702

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

AbstractThe13C NMR spectra of tricyclo[4.2.1.02,5]nonanes and tetracyclo[5.4.1.02,6.08,11]dodecanes and their dimethyl derivatives were measured to demonstrate the four‐membered ring annelation effects on the bicyclo[2.2.1]heptane skeleton, and the steric δ‐syneffects of the methyl groups attached to the four‐membered ring on the bridge carbons in these s

ISSN:0030-4921    

DOI:10.1002/mrc.1270220703

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

AbstractThe influence of hydrogen bond formation on13C chemical shifts at the α and β positions of triethylamine and tri‐n‐butylamine has been investigated by dipole moment measurements and CNDO/2 calculations. It has been shown that a hydrogen bridge dipole moment occurs during complexation. Moreover, the change observed in the C‐αC‐β bond dipole moment is proportional to the hydrogen bridge dipole moment, but is approximately 100 times smaller. This change has been related to differences between the13C chemical shifts at the α and β posi

ISSN:0030-4921    

DOI:10.1002/mrc.1270220704

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

AbstractSix of the eight possible diastereoisomeric 5‐methylperhydropyrido[3,2,1‐i,j][3,1]benzoxazines have been synthesized, and the utility of the C‐3 methylene proton NMR parameters [J(3ax3eq) and Δ3ax3eq] in the assignment of configurations has been demons

ISSN:0030-4921    

DOI:10.1002/mrc.1270220705

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

AbstractThe13C FT NMR spectra of β‐D‐glucopyranosides (including their tetraacetates) of several secondary allylic and benzylic alcohols were compared with those of methyl β‐D‐glucopyranoside and the corresponding parent alcohols. The characeristic glucosidation shifts observed for these alcohols may be applicable to the determination of the absolute configuration of the hydroxy group in these

ISSN:0030-4921    

DOI:10.1002/mrc.1270220706

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

AbstractThe1H and13C NMR spectra of thetrans,trans‐,cis,cis‐ andcis‐C‐3–C‐4,trans‐C‐7–C‐8‐germacrones and of thecis‐C‐2–C‐3,trans‐C‐7–C–8,trans‐C‐2–C‐3,cis‐C‐7–C‐8‐ andcis,cis‐isogermacrones are analysed. The last two isogermacrones are new compounds. The C‐2–C‐3 double bond in the previously described isogermacrone is found to be ofcisc

ISSN:0030-4921    

DOI:10.1002/mrc.1270220707

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

AbstractThe average conformations of methyl esters of some aliphaticerythro‐ andthreo‐dichlorocarboxylic acids in dilute carbon tetrachloride solutions have been determined from the vicinal proton–proton coupling constants and1H NMR shifts. The13C shift differences between theerythroandthreoforms are compared and discussed with regard to the differences in the average conforma

ISSN:0030-4921    

DOI:10.1002/mrc.1270220708

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

Abstract13C NMR spectra ofp‐ andm‐substituted phenylN‐methylcarbamates, phenylN,N‐dimethylcarbamates andp‐ andm‐substituted phenyl propionates were recorded, and theirpara13C SCS (substituent chemical shifts) were analysed by DSP (dual substituent parameters) and DSP‐NLR (non‐linear resonance) equations. It was found that the fixed substituent Y, OCONHCH3, OCON(CH3)2and OCOC2H5, were all mild in the sense that DSP analysis gave a good correlation, leaving little room for improvement by the DSP‐NLR treatment. Further, the three series of compounds gave similar ρIand ρRvalues (paraderivatives, 3.2–3.3 and 17.7–18.0;metaderivatives, 5.1–5.2 and 21.8–22.0). Examination of the corresponding analyses of similar compounds indicated that the ρIand ρRvalues and, hence, their ratio ρR/ρR= λ, depended primarily on the nature of the atom through which the fixed substituent Y (e.g. α‐C, α‐N and α‐O) was bonded to the aromatic ring when the Y substituents are mild. The extent of this tendency for compounds w

ISSN:0030-4921    

DOI:10.1002/mrc.1270220709

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

AbstractThe1H and13C NMR spectra of carminic acid were completely assigned, thus confirming its structure and the conformation of the glucose residue.

ISSN:0030-4921    

DOI:10.1002/mrc.1270220710

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY

摘要:

AbstractThe complete assignment of the13C NMR spectrum of longifolene was achieved from double quantum coherence measurements, while combined evaluation of a1H13C heteronuclear chemical shift correlation diagram and a homonuclear1HJ‐resolved diagram provided all proton chemical shifts. Conformational information on the seven‐membered ring of the tricyclic sesquiterpene was obtained from proton chemical shift considera

ISSN:0030-4921    

DOI:10.1002/mrc.1270220711

出版商:John Wiley&Sons Limited    

年代:1984

数据来源: WILEY